Does coffee make you fat?

Coffee is king at Seven Sisters Coffee House in the Mills 50 district of Orlando. But owner Alisha Kearns isn't buying the theory that black coffee could make you fat. “I do believe if you're mixing coffee with milks, and half-and-halves, and creams, and you're having one every day, I'm sure that would contribute to it. As far as caffeine and coffee itself, I have not researched that or heard of any of that,” says Kearns.

Few people have. But since the 1980s, Dr. Ann de Wees Allen has studied caffeine's effect on humans. “Coffee will make you fatter than a pig. Coffee will make you fatter than eating five hot fudge sundaes. That's the mechanism that the human body works with,” says Dr. Allen.

Dr. Allen is the Chief of Biomedical Research at the Glycemic Research Institute near Tampa. "When one fat cell touches another fat cell, guess what ladies? That's the trigger in our bodies to make cellulite. Every fat cell in the human body has a key code. When you turn that key code in the human body, the actual hormone is called Lipoprotein Lipase, and we call that the gatekeeper for fat storage in the fat cell. When you turn that nasty little key code for LPL, the fat cell says, ‘Yeah! Come on in baby!’”

Orlando-based registered dietitian, Tara Gidus, doesn't buy it though. She says Americans drink so much coffee, that dietitians would firmly know if it’s a major contributor to obesity.

"Too many skinny people drink it," she submits. “There's some hypothesis out there that when we eat food that doesn't have any calories, our body is still releasing insulin, and that insulin is then looking for something to store as fat. But I find it hard to believe that you're actually going to get fat from consuming something that is calorie free. We know that its calories in versus calories out,” says Gidus.

Karen Beerbower, a registered dietitian in Winter Park, believes coffee could lead to weight gain if you're putting in sweeteners.

Even no-calorie sweeteners cause cravings.

“If that sweetness then stays with you, and you're looking later for other foods that are also sweet, then you'll take in more calories a day,” says Beerbower.

“A product, a food, or a beverage doesn't have to have any calories, any carbs, or any sugar to trigger the key code. When something goes in the mouth, it has a choice: does it burn as energy, or does it go in a fat cell? Those are the choices it has,” submits Dr. Allen.

If coffee is staying in your life, Gidus recommends no more than two cups a day. Dr. Allen says: add sugar to the black coffee, or some low fat milk. Protein, she says, helps blunt the fat cell trigger.